Help with getting memory card to work

HiIm trying to copy the games on one memory card to another for a ds lite but when I put it in the ds I get an error message. When Ive tried copying the DS_MENU.SYS file over I get a message saying that I cant copy all of the data accross. What do I need to do??CheersPost Merge: [time]1267807253[/time]
The message on the ds says: Couldnt find_DS_MENU.DAT

Reformat the card an try again.

Ive tried that but didnt work. Im try to reinstall the firmware but when I download it there are loads of files. Do I copy all of them to the memory card or do they need to go in a folder?

Which firmware and which card do you use?

Here is an simple topic that you can follow (load errors):
http://forum.romulation.net/index.php?topic=35592.msg642749#msg642749